struct User {
	name          string
	age           int
	is_registered bool
}

// return a modified version of an object
fn register(u User) User {
	return User{
		...u // 
		is_registered: true
	}
}

fn main() {
	mut user := User{
		name: 'abc'
		age: 23
	}
	user2 := register(user)
	println(user)
	println(user2)
}
